Facilitating recovery in a coordinated timing network

Abstract

Recovery is provided in a timing network. A configuration is defined for that network, and in that configuration, an active primary server is identified that provides a clock source for the network. Additionally, an alternate server is identified that can perform the role of the active primary server, should the active primary server fail. In response to a failure of the primary server, the alternate server detects the failure and performs takeover of the primary server.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims priority to U.S. Provisional Application No. 60 / 887,586, entitled “FACILITATING RECOVERY IN A COORDINATED TIMING NETWORK”, filed Jan. 31, 2007, which is hereby incorporated herein by reference in its entirety.TECHNICAL FIELD[0002]This invention relates, in general, to time synchronization within and across a network of processing units, and in particular, to facilitating recovery within the network.BACKGROUND OF THE INVENTION[0003]For performance and data integrity, computing systems that access shared data, such as a Sysplex offered by International Business Machines Corporation, Armonk, N.Y., must be able to maintain time of day (TOD) clock synchronization to an accuracy that is better than best case communication time between the systems. Currently, in one example, to meet the synchronization requirements, a timer, such as the IBM Sysplex Timer®, is used. This timer requires expensive dedicated timing links and ...

AI Technical Summary

Benefits of technology

[0005]Based on the foregoing, a need exists for a capability that facilitates the providing of time synchronization. In one example, a need exists for a capability that specifies a single active stratum-1 server in a timing network that ensures that the servers in the network use the same primary reference time to synchronize clocks. A further need exists for a facility to recover from a failed active stratum-1 server.

Problems solved by technology

This timer requires expensive dedicated timing links and a separate external box.

Networks, such as the Network Timing Protocol (NTP), provide time synchronization, but do not meet the accuracy requirements of high-end systems.

This is a problem for those systems that do not have a capability to attach to external time servers that provide this level of accuracy.

Further, a requirement of GPS receivers or similar attachment on each system may be considered infeasible for maintenance, security and reliability reasons.

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